Miniature bulb and socket construction



Feb. 20, 1940. M. KLEIN El AL MINIATURE BULB AND SOCKET CONSTRUCTIONFiled Nov. 29, 1938 Patented Feb. 20, 1940 2,190,875

UNITED STATES PATENT OFFICE MINIATURE BULB AND SOCKET CONSTRUCTIONMaximilian Klein, Sellersville, and William E. Pfefier, South Perkasie,Pa., assignors to United States Gauge Company, Sellersville, Pa acorporation of Pennsylvania Application November 29, 1938, Serial No.243,048

' 6 Claims. (Cl. 176-32) The present invention relates to a novelelecview through a bulb socket made in accordance tric lamp and socketstructure especially dewith the present invention and illustrating thesigned for the illumination of instriunents, such novel bulb inoperative relation thereto. as gauges of all kinds. electricalindicating in- Figure 2 is an enlarged transverse sectional struments,clocks or the like. More particularly, view of the novel bulb assemblyof the present 5 the present invention relates to a novel miniainventionillustrating the manner of insulating ture lamp and socket structureadapted for use the contact elements from each other and of in theillumination of dial and pointer instrusecuring the glass bulb assemblyin place. ments, which permits ready application of the Figure 3 is aview of the bulb of Figure 2.

l0 lamp to the socket with the lamp bulb extending as seen from thefront of the bulb. away from the part that is gripped by the fingersFigure 4 is a view of the bulb of Figure 2 as in inserting the lamp inthe instrument. seen from the rear of the bulb.

Electrical bulbs for indicating instruments are Figure 5 is a viewsimilar to Figure 2 illusextremely small, having an overall length oftrating a modified form of bulb'assembly. approximately one-half an inchand a diameter With continued reference to the drawing 15 ofapproximately one-eighth of an inch. As wherein like reference numeralsare used to ina result of the small size of these bulbs, diflidicate thesame parts throughout the several culty has been experienced inassembling the figures, numeral ill indicates generally a lamp glassbulb with its extremely fine filaments in made in accordance with thepresent invention, the bulb base. v and numeral ll indicates generallythe novel 20 It is a primary object of the present invention socket ofthe present invention. to provide a simple base structure that will Lampit! comprises a glass bulb l2 having the enable ready assembly andconnection of the usual filament l3 therein and protruding filaglassbulb and filament to the base. ment connections l4 and I5 extending fromthe A further important object of the present inrear of the glass bulb.Glass bulb i2 is pref- 25 vention resides in the provision of anelectric erably manufactured in accordance with well lamp or baseassembly having one contact in known practices and is associated withthe novel the form of a sleeve at the front end of the bulb baseassembly l6 of the present invenassembly, and the other contact likewiseof tion in the following manner:

go sleeve-like form but disposed at the rear end Base assembly l6comprises a metal sleeve ll of the assembly, so as to provide theperipheral having an annular flange l8 at one end theremargin of thebase. of. Sleeve l'l comprises one contact element for A further objectof the present invention rebulb i0 and is connected to filament lead i isides in th provision of an electrical lamp base by a suitable solderingoperation at is.

made up of three relatively simple sleeve-like ele- After sleeve I1 isconnected to filament lead 35 ments designed to be held in assembledrelation 14, insulating sleeve 2i is telescoped thereon with each otherand with a suitable cement until the shoulder i8 abuts against the end22 serving to encase the bulb at one end and thus of sleeve 2|.

provide the lamp base. The assembled glass bulb i2, sleeve. H and Stillanother object of the present invention sleeve 2| is then provided witha further sleeve 40 resides in the provision of a novel combination 23having an annular flange 24 at one end thereof holding cap and lampdesigned to permit of. Sleeve 23 is also provided with a shoulder easyreplacement of the lamp in the cap. 24a designed to abut end 25 ofsleeve 2|. A

A further object of the present invention resplit ring 24b is looselydisposed on the portion 5 sides in the novel association of a socket,proof sleeve 23 between flange and shoulder 24a.

vided by a bore in the casing of an indicating Ring 24b in its expandedposition extends be or light instrument, and a miniature lamp and yondthe periphery of sleeve 2| and flange 24 lamp holder permittingillumination of the infor a purpose to be presently pointed out. Sleevestrument interior upon assembly of the lamp and 23 with ring 24b inplace is forced into the holder in said bore. opposite end of sleeve 2|until shoulder 24a 50 Further objects of the invention will appear abutsend25 of sleeve 2i. Filament lead i5 is from the following descriptionwhen read in then soldered to sleeve 23 at 28. Bulb assembly conjunctionwith the appended claims and at- III is then filled with a suitablecement 21 by tached drawing wherein: pouring the cement in its plasticcondition into Figure 1 is an enlarged transverse sectional the openrear end of bulb assembly [0. Cement 55 ring 5| fits' recess 33 snuglyso as to be retained by 21 completely fillsthe space between glass bulb|2 andsleeves l1, 2| and 23 so as to firmly connect these elementstogether.

From the above description it will be clear that.

bulb I0 is made of relatively few and simple parts, and that, due to thefact that the various parts are readily accessible during the assemblyoperation, very little difilculty' is experienced in making the solderedconnections I9 and 26, and in assembling the glass bulb |2 with its baseI6.

While bulb 0 may be used in any suitable socket structure, the socketstructure U of the present invention is at present preferred. Socket IIis specifically described and claimed in applicants' co-pendingapplication Serial No. 243,047, filed on even date herewith and entitledMiniature bulb and socket construction. Socket comprises a body portion3| of insulating material having a bore 32 therein. Body portion 3| maybe formed as an integral part of the casing of an indicating instrument,which is to be illuminated by the lamp of the present invention. Theupper end of bore 32 is preferably recessed, as at 33 to provide anannular shoulder 34. At suitable points in the interior of body 3| thewalls of bore 32 are provided with longitudinally extending grooves 35and 35. Grooves 35 and 36 receive electrical conductors 31 and 38 whichare connected in any suitable manner to a source of electrical energy.

Conductor 31 preferably constitutes the live conductor and is providedwith an annular contact portion 39 having a centrally disposed opening4| therein. Inorder to properly position contact 39 in bore 32,conductor 31 is secured to an insulating sleeve 42 as by means ofsuitable arms 43 carried by the conductor which pass through suitableapertures 44 in the wall of sleeve 42. Arms 43 are bent over so as toclamp portion 45 of sleeve 42 at 46. Sleeve 42 with conductor 31 securedthereto is then inserted into bore 32, preferably from the lower end,and forced upwardly through bore 32 until contact 39 is at the properlevel. While a frictional fit between sleeve 42 and bore 32 is usuallysumcient to retain the sleeve in proper position, suitable cement maybeused.

Conductor 33 in groove 36 extends beyond the shoulder 34 and is thenbent over to provide a portion 48 in engagement with shoulder 34 and aportion 49 in engagement with the wall ofrecess 33 of bore 32. A metalring 5| having internal threads 52 therein 'is positioned'in recess 33and clamps portions 48 and 49 ofconduit 38 in place.

Metal ring 5| may be associated with body 3| in any suitable manner.Preferably, however, the

friction.v The body 3| is made of insulating material such as Bakelite",it is to be understood that ring 5| may be cemented to said body ifdesired.

Ring 5| in the illustrated embodiment is adapted to receive anexternally threaded lamp-receiving metal cap 53 having an internal bore54 therein. Bore 54 receives base I6 of lamp l0. As base I5 is insertedinto bore 54, ring 24b is contracted and, due to its tendency to expandfrictionally, secures lamp ID in cap 53 so as to permit handling of theassembly as a unit. In its final position in cap 53 lamp l0 engages thetapered walls 55 of cap 53 along the corners of contact 24. Engagementof walls 54 and contact 24 insures an adequate electrical contactbetween the cap and the lamp. Cap 53 completes the return circuit fromfilament l3, contact 24 to metal ring 5|, and conduit 38. When the cap53 is firmly screwed in the ring 5|, the flange l3 of contact sleeve |'Ibears against contact ring 39, current flowing to the filament fromconductor 31, through ring 39, sleeve to the filament l3. It will beunderstood that a suitable opening is provided in the wall of the socketso that the rays of light emanat- I ing from the lamp may pass in thedirection needed to properly illuminate the dial and/or pointer of theinstrument, all as more completely described in the application ofMaximilian Klein and William E. Pfeffer, entitled Illuminatingindicating'instruments, filed on even date herewith.

While the socket ll of the present invention has been described as beingformed from a body 3| of insulating material, it will be appreciatedthat body 3| may be formed of metal by use of a suitable insulatedconduit .31. If such a structure is resorted to, ring 5| and conduit 38may be omitted and the cap 53 may be screwed directly semblysubstantially like that shown in Figures 1 to 4. This form of theinvention differs from that previously described in that sleeve 23 isomitted and a second sleeve I1 is substituted therefor. In all otherrespects, this form of the invention is like that previously described.As a consequence, the same reference numerals have been employed and adetailed description is believed to be unnecessary.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodimentsare therefore, to be considered in all respects asillustrative and not restrictive, the scope of the inventionbeing-indicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. A lamp, comprising a closed bulb having a filament therein, and abase consisting of two conductor sleeves disposed in spaced relationendwise of said bulb, said sleeves being of equal diameter, aninsulating sleeve electrically separating said conductor sleeves andforming with said conductor sleeves a base having smooth externalsurconductor sleeves.

terial cooperatingwith said sleeves to-complete said base, saidconductor sleeves and said insulating sleeve being formed to providesaid base with a smooth and uninterrupted external surface.

4. An electric lamp having a base including two identical axiallyseparated contacts each of which is in the form of a sleeve having oneend terminating in an external annular flange, and an insulating sleeveseparating said contacts, said base being adapted for assembly with astandard bulb structure by telescoping either end of said sleeve overthe predetermined end of said bulb structure.

5. An electric lamp, comprising a bulb having a filament therein and abase consisting of two conductor sleeves disposed in spaced relationendwise of said bulb, an insulating sleeve electrically separating saidconductor sleeves, said conductor sleeves and insulating sleeve togetherforming a smooth external annular wall, a split snap ring interposedbetween a portion of one of said conductor sleeves and said insulatingsleeve, connections between said filament and said conductor sleeves,and cementitious material in certain of said sleeves providing a closurecompletely housing one end of said bulb.

6. A lamp and cap assembly, consisting in a cap having a smoothcylindrical bore for the removable reception of the base of said lamp, anormally expanded snap ring mounted in the external wall 01 said basefor frictionally engaging the wall of said bore to removably secure thelamp in said cap, a threaded connection on said cap for connection to asocket and a portion on said cap providing a finger grip to permit thecap with the bulb therein to be threaded into said socket;

MAXIMILIAN KLEIN. WILLIAM E. PFEFFER.

